feat(plat/imx/imx8m/imx8mm): add support for measured boot

Add helper functions to generate event log for imx8mm
when MEASURED_BOOT=1.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Change-Id: Ifc947d749055787fbda0b39170aa2eb8865b7802
diff --git a/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c b/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c
new file mode 100644
index 0000000..8b2fdd6
--- /dev/null
+++ b/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2022, Linaro.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#if MEASURED_BOOT
+#include <common/desc_image_load.h>
+#endif
+#include <common/fdt_wrappers.h>
+#include <libfdt.h>
+
+#define DTB_PROP_HW_LOG_ADDR	"tpm_event_log_addr"
+#define DTB_PROP_HW_LOG_SIZE	"tpm_event_log_size"
+
+#if MEASURED_BOOT
+
+static int imx8m_event_log_fdt_init_overlay(uintptr_t dt_base, int dt_size)
+{
+	int ret;
+	int offset;
+	void *dtb = (void *)dt_base;
+
+	ret = fdt_create_empty_tree(dtb, dt_size);
+	if (ret < 0) {
+		ERROR("cannot create empty dtb tree: %s\n",
+		       fdt_strerror(ret));
+		return ret;
+	}
+
+	offset = fdt_path_offset(dtb, "/");
+	if (offset < 0) {
+		ERROR("cannot find root of the tree: %s\n",
+		       fdt_strerror(offset));
+		return offset;
+	}
+
+	offset = fdt_add_subnode(dtb, offset, "fragment@0");
+	if (offset < 0) {
+		ERROR("cannot add fragment node: %s\n",
+		       fdt_strerror(offset));
+		return offset;
+	}
+
+	ret = fdt_setprop_string(dtb, offset, "target-path", "/");
+	if (ret < 0) {
+		ERROR("cannot set target-path property: %s\n",
+		       fdt_strerror(ret));
+		return ret;
+	}
+
+	offset = fdt_add_subnode(dtb, offset, "__overlay__");
+	if (offset < 0) {
+		ERROR("cannot add __overlay__ node: %s\n",
+		       fdt_strerror(offset));
+		return ret;
+	}
+
+	offset = fdt_add_subnode(dtb, offset, "tpm_event_log");
+	if (offset < 0) {
+		ERROR("cannot add tpm_event_log node: %s\n",
+		       fdt_strerror(offset));
+		return offset;
+	}
+
+	ret = fdt_setprop_string(dtb, offset, "compatible",
+				 "arm,tpm_event_log");
+	if (ret < 0) {
+		ERROR("cannot set compatible property: %s\n",
+		       fdt_strerror(ret));
+		return ret;
+	}
+
+	ret = fdt_setprop_u64(dtb, offset, "tpm_event_log_addr", 0);
+	if (ret < 0) {
+		ERROR("cannot set tpm_event_log_addr property: %s\n",
+		       fdt_strerror(ret));
+		return ret;
+	}
+
+	ret = fdt_setprop_u32(dtb, offset, "tpm_event_log_size", 0);
+	if (ret < 0) {
+		ERROR("cannot set tpm_event_log_size property: %s\n",
+		       fdt_strerror(ret));
+		return ret;
+	}
+
+	return ret;
+}
+
+/*
+ * Write the Event Log address and its size in the DTB.
+ *
+ * This function is supposed to be called only by BL2.
+ *
+ * Returns:
+ *	0 = success
+ *    < 0 = error
+ */
+static int imx8m_set_event_log_info(uintptr_t config_base,
+				  uintptr_t log_addr, size_t log_size)
+{
+	/* As libfdt uses void *, we can't avoid this cast */
+	void *dtb = (void *)config_base;
+	const char *compatible_tpm = "arm,tpm_event_log";
+	uint64_t base = cpu_to_fdt64(log_addr);
+	uint32_t sz = cpu_to_fdt32(log_size);
+	int err, node;
+
+	err = fdt_open_into(dtb, dtb, PLAT_IMX8M_DTO_MAX_SIZE);
+	if (err < 0) {
+		ERROR("Invalid Device Tree at %p: error %d\n", dtb, err);
+		return err;
+	}
+
+	/*
+	 * Verify that the DTB is valid, before attempting to write to it,
+	 * and get the DTB root node.
+	 */
+
+	/* Check if the pointer to DT is correct */
+	err = fdt_check_header(dtb);
+	if (err < 0) {
+		WARN("Invalid DTB file passed\n");
+		return err;
+	}
+
+	/*
+	 * Find the TPM node in device tree.
+	 */
+	node = fdt_node_offset_by_compatible(dtb, -1, compatible_tpm);
+	if (node < 0) {
+		ERROR("The compatible property '%s' not%s", compatible_tpm,
+			" found in the config\n");
+		return node;
+	}
+
+	err = fdt_setprop(dtb, node, DTB_PROP_HW_LOG_ADDR, &base, 8);
+	if (err < 0) {
+		ERROR("Failed to add log addr err %d\n", err);
+		return err;
+	}
+
+	err = fdt_setprop(dtb, node, DTB_PROP_HW_LOG_SIZE, &sz, 4);
+	if (err < 0) {
+		ERROR("Failed to add log addr err %d\n", err);
+		return err;
+	}
+
+	err = fdt_pack(dtb);
+	if (err < 0) {
+		ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, err);
+		return err;
+	}
+
+	/*
+	 * Ensure that the info written to the DTB is visible
+	 * to other images.
+	 */
+	flush_dcache_range(config_base, fdt_totalsize(dtb));
+
+	return err;
+}
+
+/*
+ * This function writes the Event Log address and its size
+ * in the QEMU DTB.
+ *
+ * This function is supposed to be called only by BL2.
+ *
+ * Returns:
+ *	0 = success
+ *    < 0 = error
+ */
+int imx8m_set_nt_fw_info(size_t log_size, uintptr_t *ns_log_addr)
+{
+	uintptr_t ns_addr;
+	int err;
+
+	assert(ns_log_addr != NULL);
+
+	ns_addr = PLAT_IMX8M_DTO_BASE + PLAT_IMX8M_DTO_MAX_SIZE;
+
+	imx8m_event_log_fdt_init_overlay(PLAT_IMX8M_DTO_BASE,
+					  PLAT_IMX8M_DTO_MAX_SIZE);
+
+	/* Write the Event Log address and its size in the DTB */
+	err = imx8m_set_event_log_info(PLAT_IMX8M_DTO_BASE,
+					ns_addr, log_size);
+
+	/* Return Event Log address in Non-secure memory */
+	*ns_log_addr = (err < 0) ? 0UL : ns_addr;
+	return err;
+}
+
+#endif /* MEASURED_BOOT */
diff --git a/plat/imx/imx8m/imx8m_measured_boot.c b/plat/imx/imx8m/imx8m_measured_boot.c
new file mode 100644
index 0000000..ec61606
--- /dev/null
+++ b/plat/imx/imx8m/imx8m_measured_boot.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ * Copyright (c) 2022, Linaro.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <string.h>
+
+#include "./include/imx8m_measured_boot.h"
+#include <drivers/measured_boot/event_log/event_log.h>
+#include <plat/arm/common/plat_arm.h>
+
+/* Event Log data */
+static uint8_t event_log[PLAT_IMX_EVENT_LOG_MAX_SIZE];
+
+/* FVP table with platform specific image IDs, names and PCRs */
+static const event_log_metadata_t imx8m_event_log_metadata[] = {
+	{ BL31_IMAGE_ID, EVLOG_BL31_STRING, PCR_0 },
+	{ BL32_IMAGE_ID, EVLOG_BL32_STRING, PCR_0 },
+	{ BL32_EXTRA1_IMAGE_ID, EVLOG_BL32_EXTRA1_STRING, PCR_0 },
+	{ BL32_EXTRA2_IMAGE_ID, EVLOG_BL32_EXTRA2_STRING, PCR_0 },
+	{ BL33_IMAGE_ID, EVLOG_BL33_STRING, PCR_0 },
+	{ EVLOG_INVALID_ID, NULL, (unsigned int)(-1) }	/* Terminator */
+};
+
+const event_log_metadata_t *plat_event_log_get_metadata(void)
+{
+	return imx8m_event_log_metadata;
+}
+
+int plat_mboot_measure_image(unsigned int image_id, image_info_t *image_data)
+{
+	/* Calculate image hash and record data in Event Log */
+	int err = event_log_measure_and_record(image_data->image_base,
+					       image_data->image_size,
+					       image_id);
+	if (err != 0) {
+		ERROR("%s%s image id %u (%i)\n",
+		      "Failed to ", "record", image_id, err);
+		return err;
+	}
+
+	return 0;
+}
+
+void bl2_plat_mboot_init(void)
+{
+	event_log_init(event_log, event_log + sizeof(event_log));
+	event_log_write_header();
+}
+
+void bl2_plat_mboot_finish(void)
+{
+	int rc = 0;
+
+	/* Event Log address in Non-Secure memory */
+	uintptr_t ns_log_addr;
+
+	/* Event Log filled size */
+	size_t event_log_cur_size;
+
+	event_log_cur_size = event_log_get_cur_size(event_log);
+
+	rc = imx8m_set_nt_fw_info(event_log_cur_size, &ns_log_addr);
+	if (rc != 0) {
+		ERROR("%s(): Unable to update %s_FW_CONFIG\n",
+		      __func__, "NT");
+		/*
+		 * It is a fatal error because on i.MX U-boot assumes that
+		 * a valid event log exists and will use it to record the
+		 * measurements into the fTPM.
+		 */
+		panic();
+	}
+
+	/* Copy Event Log to Non-secure memory */
+	(void)memcpy((void *)ns_log_addr, (const void *)event_log,
+		     event_log_cur_size);
+
+	/* Ensure that the Event Log is visible in Non-secure memory */
+	flush_dcache_range(ns_log_addr, event_log_cur_size);
+
+	dump_event_log((uint8_t *)event_log, event_log_cur_size);
+}
diff --git a/plat/imx/imx8m/imx8mm/include/platform_def.h b/plat/imx/imx8m/imx8mm/include/platform_def.h
index 6709678..300ef9e 100644
--- a/plat/imx/imx8m/imx8mm/include/platform_def.h
+++ b/plat/imx/imx8m/imx8mm/include/platform_def.h
@@ -152,3 +152,7 @@
 #define MAX_IO_HANDLES			3U
 #define MAX_IO_DEVICES			2U
 #define MAX_IO_BLOCK_DEVICES		1U
+
+#define PLAT_IMX8M_DTO_BASE		0x53000000
+#define PLAT_IMX8M_DTO_MAX_SIZE		0x1000
+#define PLAT_IMX_EVENT_LOG_MAX_SIZE	UL(0x400)
diff --git a/plat/imx/imx8m/imx8mm/platform.mk b/plat/imx/imx8m/imx8mm/platform.mk
index ac5a809..cd8de89 100644
--- a/plat/imx/imx8m/imx8mm/platform.mk
+++ b/plat/imx/imx8m/imx8mm/platform.mk
@@ -8,11 +8,14 @@
 				-Iplat/imx/imx8m/include		\
 				-Iplat/imx/imx8m/imx8mm/include		\
 				-Idrivers/imx/usdhc			\
-				-Iinclude/common/tbbr
+				-Iinclude/common/tbbr			\
+				-Iinclude/lib/libfdt
 
 # Include GICv3 driver files
 include drivers/arm/gic/v3/gicv3.mk
 
+include lib/libfdt/libfdt.mk
+
 IMX_GIC_SOURCES		:=	${GICV3_SOURCES}			\
 				plat/common/plat_gicv3.c		\
 				plat/common/plat_psci_common.c		\
@@ -43,6 +46,7 @@
 
 ifeq (${NEED_BL2},yes)
 BL2_SOURCES		+=	common/desc_image_load.c			\
+				common/fdt_wrappers.c				\
 				plat/imx/common/imx8_helpers.S			\
 				plat/imx/common/imx_uart_console.S		\
 				plat/imx/imx8m/imx8mm/imx8mm_bl2_el3_setup.c	\
@@ -148,3 +152,14 @@
 
 EL3_EXCEPTION_HANDLING := 1
 SDEI_SUPPORT := 1
+
+ifeq (${MEASURED_BOOT},1)
+    MEASURED_BOOT_MK := drivers/measured_boot/event_log/event_log.mk
+    $(info Including ${MEASURED_BOOT_MK})
+    include ${MEASURED_BOOT_MK}
+
+BL2_SOURCES		+=	plat/imx/imx8m/imx8m_measured_boot.c	\
+				plat/imx/imx8m/imx8m_dyn_cfg_helpers.c	\
+				${EVENT_LOG_SOURCES}
+
+endif
diff --git a/plat/imx/imx8m/include/imx8m_measured_boot.h b/plat/imx/imx8m/include/imx8m_measured_boot.h
new file mode 100644
index 0000000..2ec0c46
--- /dev/null
+++ b/plat/imx/imx8m/include/imx8m_measured_boot.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2022, Linaro
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef IMX8M_MEASURED_BOOT_H
+#define IMX8M_MEASURED_BOOT_H
+
+#include <stdint.h>
+
+#include <arch_helpers.h>
+
+int imx8m_set_nt_fw_info(size_t log_size, uintptr_t *ns_log_addr);
+
+#endif /* IMX8M_MEASURED_BOOT_H */